Antacid Tablet Race

TOPIC: Rocket fuels and propellants

Objective: To demonstrate how increasing the surface area of a chemical increases its reaction rate.

Description: A whole antacid tablet and a crushed tablet are added to separate beakers of water so that their relative reaction rates can be compared.

EDITED BY: Roger Storm, NASA Lewis Research Center


Materials:

Procedure:

  1. Fill both beakers about half full with water of the same temperature.
  2. Wrap paper around one antacid tablet. Place the packet on a hard surface and crush the tablet by pressing on it with the wood block.
  3. Open the paper packet with the crushed tablet and hold it over one of the beakers. Pour the powder in the water and time how long it takes for the powder to dissolve.
  4. Pick up a whole tablet and drop it into the second beaker of water. Time how long it takes to dissolve completely.

Discussion: This activity demonstrates how increasing the surface area of an antacid tablet by crushing it into a powder increases the rate in which it dissolves in water. This is a similar situation to the way the thrust of a rocket is increased by increasing the burning surface of its propellants. Increasing the burning surface increases its burning rate since more fuel becomes exposed to oxygen . In solid rockets, a hollow core extending the length of the propellant will permit more propellant to burn at a time. This increases the acceleration of the gases produced as they leave the rocket engine. Liquid propellants are sprayed into the combustion chamber of a liquid propellant rocket to increase their surface area. Smaller droplets react more quickly than do large ones, increasing the acceleration of the escaping gases.

Teaching Notes and Questions:


EVOLUTION OF CARBON DIOXIDE LAB A chemistry lab

GO BACK TO THE ROCKET ACTIVITIES


Aerospace Education
Services Project
 Oklahoma State University